com.brackeen.javagamebook.util
Class ThreadPool

java.lang.Object
  java.lang.ThreadGroup
      com.brackeen.javagamebook.util.ThreadPool

All Implemented Interfaces:

java.lang.Thread.UncaughtExceptionHandler

Direct Known Subclasses:

SoundManager

public class ThreadPool
extends java.lang.ThreadGroup

A thread pool is a group of a limited number of threads that are used to execute tasks.

Nested Class Summary

private class

ThreadPool.PooledThread A PooledThread is a Thread in a ThreadPool group, designed to run tasks (Runnables).

Field Summary

private boolean	isAlive
private java.util.LinkedList	taskQueue
private int	threadID
private static int	threadPoolID

Constructor Summary

ThreadPool(int numThreads)
Creates a new ThreadPool.

Method Summary

void	close() Closes this ThreadPool and returns immediately.
protected java.lang.Runnable	getTask()
void	join() Closes this ThreadPool and waits for all running threads to finish.
void	runTask(java.lang.Runnable task) Requests a new task to run.
protected void	threadStarted() Signals that a PooledThread has started.
protected void	threadStopped() Signals that a PooledThread has stopped.

Methods inherited from class java.lang.ThreadGroup

activeCount, activeGroupCount, allowThreadSuspension, checkAccess, destroy, enumerate, enumerate, enumerate, enumerate, getMaxPriority, getName, getParent, interrupt, isDaemon, isDestroyed, list, parentOf, resume, setDaemon, setMaxPriority, stop, suspend, toString, uncaughtException

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

isAlive

private boolean isAlive

taskQueue

private java.util.LinkedList taskQueue

threadID

private int threadID

threadPoolID

private static int threadPoolID

Constructor Detail

ThreadPool

public ThreadPool(int numThreads)

Creates a new ThreadPool.

Parameters:

numThreads - The number of threads in the pool.

Method Detail

runTask

public void runTask(java.lang.Runnable task)

Requests a new task to run. This method returns immediately, and the task executes on the next available idle thread in this ThreadPool.

Tasks start execution in the order they are received.

Parameters:

task - The task to run. If null, no action is taken.

Throws:

java.lang.IllegalStateException - if this ThreadPool is already closed.

getTask

protected java.lang.Runnable getTask()
                              throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

close

public void close()

Closes this ThreadPool and returns immediately. All threads are stopped, and any waiting tasks are not executed. Once a ThreadPool is closed, no more tasks can be run on this ThreadPool.

join

public void join()

Closes this ThreadPool and waits for all running threads to finish. Any waiting tasks are executed.

threadStarted

protected void threadStarted()

Signals that a PooledThread has started. This method does nothing by default; subclasses should override to do any thread-specific startup tasks.

threadStopped

protected void threadStopped()

Signals that a PooledThread has stopped. This method does nothing by default; subclasses should override to do any thread-specific cleanup tasks.